Fluid operated control apparatus for clutches



March 24, 1942. r. PORSCHE 'FLUID OPERATED C ONTROL APPARATUS FORCLUTCHES Filed'Aug. 3, 1938 Patented Mar. 24, 1942 FLUID OPERATEDCONTROL APPARATUS i FOR CLUTCHES Ferdinand Porsche,Stuttgart-on-the-Neekar, Germany, assignor to Dr. Ing. h. c. F. Porsche,

company of Germany Application August 3, 1938, Serial No. 222,902 InGermany August'10, 1937 l l 9 Claims. This invention relates to uidoperated con- `trol apparatus for clutches, and has for an object toprovide such an apparatus in which a i'luid under pressure ser'ves undercontrol of theoperator to disengage or engage the clutch of a primemover such as an internal combustion engine, particularly in motorvehicles.

Another object of the invention is to provide such an apparatus in whichthe usual lubricant pump of the prime mover supplies the operating fluidfor an operating apparatus for the clutch controlling the powergenerated by said prime mover. I

yAnother object is to provide such an apparatus in which the lubricantpump normally supplies lubricant under low pressure to the bearings ofsaid prime mover (or other bearings ofsaid vehicle) and in which meansare provided for causing said pump to deliver lubricant at a higherpressure for operating said apparatus.

Another object is to provide for the release of fluid which has beendelivered to said apparatus to a lubricant supply container K preferablythrough an adjustable throttling device.

Another object is to provide control valve means actuated by` theoperator which normally permits direct delivery of lubricant from thepump to the bearings, and which in another position cuts off such directow so'that delivery,of

oil to said bearings occurs through a relief valvev so that a higherpressure of lubricant between the pump and the relief valve is madeavailable for actuating said clutch operating apparatus.

Another object is to provide such a control valve which, when operated,interrupts the direct delivery of oil to said bearings and opens a pas`sage for the delivery of oil vfrom said pump to l said apparatus.

Another object is to provide such a valve 'so constructed and arrangedthat the pressure of the lubricant assists in the operation of the valvetoward the position in which lubricant is supplied to said apparatus.

Further objects and advantages of this invention will be apparent fromconsideration of the speciiication as illustrated by the accompanyingdrawing of possible embodiments of theinven- Germany, a

fluid may be delivered to the clutch disengaging apparatus.

In said drawing, the numeral I represents the motor. 2 and 3 arelubricating points. 4is the crank shaft with the ywheel 5, The latter isshown as provided with one member of a cone clutch, the other member ofwhich is the clutch plate 6. 1 indicates the usual clutch spring, 8 thedisengaging lever which is connected with the clutch pedal 9 through thelinkage I0 and the idle movement connection II. l

The provision of the bearings 2 and 3 with oil is accomplished throughthe conduits I4 and I9 by any suitable pump, preferably of the positivedisplacement type such 'as the gear pump I2 drawing out of the oilconta'iner I3. I'5 represents the control valve' housing. '.I'he oil mayflow at times through the slot I6 of the control slide I1 and thechannel I8 leading to the distributing conduit I9. A pressure reliefvalve 20 serves in known manner for controlling the pressure necessaryfor lubrication by permitting some of the oil to return to the sump I3when the pressure reaches the amount for which the valve has been set.From the `clutchlever or pedal 9 a link 2| leads to the lever 22 whichpresses upon the valve `I1 under action of the spring 23. In the controlvalve housing another channel 24 is -provided from which aconduit25leads to the clutch disengaging cylinder 26 in which the` clutchdisengaging piston 21 is located and which operates clutch operatinglever 8 as through the linkage members 28, 29,- and 30. A conduit 3|branches oil' from the conduit I4 and connects with the oil distributingconduit I9 through relief valve 32, which valve is adjusted for thepressure necessary for operating the piston 21. The upper part ofthecontrol slide is provided with slits 33 which vin the engaged clutchposition (Fig. 1) connects with the motor stationary, rst, that uponstarttion; in which drawing: l

Fig'. l is a longitudinal cross-sectional view illustrating more or lessschematically an illustrative form of the invention; and

Fig. 2 is a fragmentary viewof the valve mechanism and its connectingconduits, the valve slide being shown moved to a position in which 66supplied with oil.V The oil pressure, however,

ing the motor the clutch foot pedal 9 is pressed down so far that theconnection II of the link In moves the disengagingleverv 8 and therebydisengages the clutch 5, 6 against the operation .ofthe spring 1. Themotor may now be' started Y lthe valve housing I5, through slit I6 andthrough the passage I8 into .the distributing` conduit I9 from which thelubricating points 2 and 3 are also lifts the control valve slide I1upwardly so that shortly thereafter the channel I8 is closed'. Thereuponthe oil pressurgrises so that the relief valve 32 is opened and oilagain ows to the lubricating points 2 and 3, the oil being delivered atthe proper pressure necessary for lubrication in accordance with thesetting of the pressure relief valve 20. The slide valve is quicklyraised further (to the position shown in Fig. 2), until pressure oilflows through the slit I6, the passage 24, the conduit 25, and to thecylinder 26, driving the clutch disengaging piston outwardly andrelieving the stress upon the operating rods I and II through thelinkage 28, 29, and 30, so that the clutch pedal 9 may be held down bythe chauifeur without substantial stress. The reengagement of the clutchis effected by simply releasing the clutch pedal 9 so that the spring 23presses the slide valve I1 downwardly by means of the lever 22 until thechannel 24 is connected with the conduit 25 through the slits 33 and thepassage 34 connecting with the conduit 25, so that the oil may fio'wback from the clutch disengaging cylinder 26 through the conduit 25,

conduit 35, and throttle 36 to the sump I3, whereupon the clutch spring1 moves' the clutch plate B into effective position. The throttle valve36 `limits the speed of return of the oil so that the engagement Vissmooth and shock free. At the same time, the parts return to theposition shown in Fig. 1 so that the distributing conduit I9 is againconnected with the valve housing I5 through passage I8 and the slit I6.When the vehicle is in operation (motor running and clutch engaged) theparts are in the position shown in Fig. l so that the device is readyfoi service,

whereupon the operation of the clutch may beV effected repeatedlywithout tiring the operator.

Devices made in accordance with the invention are particularly useful inconnection with centrifugal clutches, in which centrifugal masses serveto increase the clutch parts engaging forces in accordance withthe speedof revolution Abecause such clutches are especially diicult to disengageunder certain circumstances.

An important feature of the invention is the means whereby operatingfluid under high pressure is provided for operating the hydraulic clutchoperating device. This permits of a much smaller cylinder and piston (ortheir equivalent) than when a vacuum device is used and also muchsmaller than when the lubricating oil at usual pressure is used. It isparticularly desirable to provide means whereby a single source ofpressure, as the usual lubricating pump, may deliver fluid at twodifferent pressures, 'one' for the points to be lubricatedand a higherpressure for actuating the operating device, which may, as a result bemade very small and light.

The application of the device is not limited to motor vehicles but isuseful in case o f shipsV and locomotives, or in any other apparatus inwhich a power unit is to be disconnected.

The construction of the pump is quite immaterial, it being possible touse pumps of other types, such as piston pumps. It is further immaterialwhich, if anylubricant points are to be supplied by the pump so that,for example, a separate pump may be provided for operating the clutch.

Furthermore, the particular construction of the control valve isunimportant as well as that of its housing and the type of operatingmeans for the control valve. It is only important that the hydraulicdevice be so arranged that ade- It will be noted that the constructionshown l and describe will serve admirably to accomplish' the objectsstated above. It is to be understood, however, that the constructiondisclosed above is intended merely as illustrative of the invention andnot as limiting as various modifications therein may be made withoutdeparting from the invention as deiine'd by a proper interpretation ofthe claims which follow.

-I claim:

l. In a device for operating clutches and the like, the combination of aprime mover, a clutch for controlling power delivered thereby, a pumpfor forcing lubricant to the bearings of said prime mover, a hydraulicclutch operating device adapted for operation by lubricant from saidpump, manual means for operating said clutch, a control valve, and meansoperated by said manual means for controlling actuation of said controlvalve from a position in which said hydraulic device is ineffective to aposition in which lubricant is supplied for actuating said hydraulicoperating device, the movement of said valve in a direction to actuatesaid hydraulic operating device being effected by the pressure of saidlubricant.

2. In a device for operating clutches and the like, the combination of asource of fluid pressure, a hydraulic operating device adapted foroperation by fluid from said source, manual means for operating saidclutch through a lost motion connection, a control valve, and means forcontrolling actuation of said control valve operated by said manualmeans, the said control valve being moved by the pressure of said fluidin a direction to permit flow of fluid from said source'to saidhydraulic operating device.

3. In a device for operating clutches and the like, the combination of aprime mover, a clutch for controlling power delivered thereby, a pumpfor forcing lubricant to the bearings of said prime mover, a hydraulicoperating device adapted for operation by the lubricant from said pumpand for operating said clutch, a control valve, means for controllingactuation of said control valve from a position in which said hydraulicdevice is ineffective to a position in which lubricant is `supplied foractuating said hydraulic operating u like, the combination of a primemover, a clutch for controlling power delivered thereby, a pump forforcing lubricant to the bearings of said prime mover, a hydraulicoperating device adapted for operation by lubricant from said pump,manual means for operating said clutch, a control valve movable from aposition in which said hydraulic device is ineffective to a position inwhich lubricant is supplied for actuating said hydraulic operatingdevice. the movement of said valve in one direction being effected bythe pressure of said lubricant, together with spring means whereby saidvalve is biased against movement by the oil pressure, and means actuatedby said means for overcoming the eilfect of said spring v manual means.

5. In a power .transmission system of the class wherein a prime moverhaving a 'plurality oi' bearing points -is adapted to supply power to aload through a normally engaged clutch, the combination of a pumpadapted to supply lubricant under pressure, a pressure responsive deviceconnected 'for disengaging said clutch,lmeans including av valve forcontrolling the path of the! supply of lubricant under pressure to saidbearing points and said pressure responsive device, and a. lever forcontrolling said valve and for mechanically disengaging said clutch.

6.1 The combination according to claim 5, in which said valve includes aslide movable between two extreme positions, in one of which it effectsa ilow of lubricant under pressure to said arings, and in the other ofwhich it permits a: flow of lubricant under pressure to said pressureresponsive device. A

- '1. The combination according to claim 5, in combination with alost-motion device between said lever and said clutch for permittingcontrol `'of said valve before disengagement of said clutch.

8. In a power transmissionsystem o1' the class said Sump,

wherein a prime mover having 'a plurality of bearing points is adaptedto supply power to a load through a normally engaged clutch, thecombination of a sump adapted to contain a lubricant. a pump adapted tosupply lubricant -under pressure from said sump, a pressure responsivedevice connected for disengaging said clutch, means including a valvefor controlling the path of the supply of lubricant under pressure tosaid bearing points and to said pressure responsive device, a conduitinterconnecting said valve with and for mechanically disengaging saidclutch, said valve having a slide Y movable between two extremepositions, in one of which it effects a iiow of lubricant under pressure.to said bearing points while connecting said pressure responsive devicethrough said conduit to said sump. and in the other' of which it permitsa ilow of lubricant under pressure to said pressure responsive device.

9. 'I'he combination accordingto claim 8, in

combination with a throttling device in said conduit for insuring a slowengagement of said clutch when said slide is in the one extremeposition. Y

FERDINAND PORSCHE.V

and a lever for controlling saidvalve

